Airplane propulsion device



*June 23, 1931. s. R. SMITH AIRPLANE PROPULSION DEVICE Filed Nov. 13, 1929 I N V EN TOR. Jazz! fidnzz.

A TTORNE Y.

I. *uNir-ED STATES T fINDIANA Patented June 23, 1931 PATENT OFFICE SAMI R.=s1vrir1a, or sour-H BEND, INDIANA, ASSIGNOR or .oNn-rounrrr .rz-o .PAU'L e.

HorF-MA ND oNE-FouivrH'ro DOROTHY B. HOFFMAN, BOTH or .SOUTH BEND,

AIRPLANE PROPULSION DEVICE Application filed-November 13, 1929. Serial'No. 406,957.

The invention relates 'to'xairplane propulsion 'devices ad'aptedto replace conventional airplane propellers, and has for its object to provide a device" of this character having aplurality ofair displacing members of U-s'haped cross section each having a Tlarge dimension leading edge and tapering from theleading edgetorthe discharge cnd:at a

suitable pitch, said members being mounted on the shaftin balanced relation.

A further object istoprovide a device of this character with which greater traction per unit of power expended, lower 'motor speed, and more effective utilization of power is obtained than with conventional screw propellers. p i

A further object is to provide a device of this character having air displacing members of 'largearea which'are constructed to'compress the air which they contact in their revolution, whereby great traction is obtained by virtueof the 'factthat said compressed air forms a heavier .and more substantial element against whichto push than atmospheric air;

A further object is to provide a device of tliischaracter having a pluralityof radial arms carrying weights at their outer ends whereby thedevice will continue to rotate for a period if the motor'stalls.

A further object is to-provide a device of thischaracter havinga rotatable shaft carrying inner and outer sets of radiallye'xtending arms on which are-mounted-in balanced relation a plurality of air displacing members whoseleading edges are carried by arms of the outer set and which taper'therefrom to the outer end of adjacent arms of the 'inner'set in counter rotation direction to.

form members of tapering semi-pocket form and of any desired pitch. Y

With the above and other objects in view,

v the invention-resides in the combination .and

arrangement of parts as hereinafter set forth, shown in the drawings, described and claimed, it being understood that changes in the precise embodiment of the invention may bemade within the scope of what is claimed without departing from the spirit of the invention.

air displacing and compressingmembers.

Referring to the drawings, which illus trate the preferredembodiment. of the inventron, the numeral 1 designates a rotatable shaft adapted to have a driving connection .with an airplane-motor in the conventional manner. Carried-"by the shaft 1 in suitably spaced relation are :an outer set 2 and :an inner set 3 of radially extending arms,;preferably disposed in parallelism :and in the axial plane of the shaft, the arms of each set beingbalanced on the shaft andbeing preferably four 'in number disposed perpendicularly with relation to each other. On

the outer end of each of the arms in the inner and outer setsare mounted weights .4

for purposes to be hereinafter set fortln The weights 4 are preferably stream-lined and L shaped in general outline, 21-11d52l'1'611101111tt3d on the arms in balanced relation. 'VVire brace members 6 aresecured tothe weights 4 by means of holes'5 formed in the ends of' f:

the weights and through which the wires pass, said wires extending between .said weights to support and brace the arms in their correct position. As shown, the'wire braces preferably extend bet-ween theadjacent arms ofthe same set and diagonally be tween adjacent arms of both sets, so that the arms of each set are braced with respect to theother arms-in the same set and-the adjacent arms of the other set.

"Two or more air displacing and compressing :members 7 formed of a strong heavy gradeof canvas or other fabric, or of some strong light metal such as duralumin,

are carried by the two sets of arms in balanced relation on'the shaft 1 as follows: Beginning at a point at the inner end of an arm of the outer set'each member .is secured to *andextendsalong saidarm to a point adjacent :the outer: end thereof, thence the'outer end thereof, thence the member extends diagonally to a point adjacent the outer end of the adjacent arm of the inner set in=counter rotation direction, thence the member is secured to and extends inwardly along said last named arm to the "inner end of said arm, thence the member extends to. u

1 many modlficatlonsn thepoint beginning, When soformed the members 7 comprise inner and outer tr angular side walls 8 and 9, respectively, andv a triangular top wall 10. Each member constructed is e -shaped in cross section, ta 7 v :similarchange's might be made. All of these pers to apoint in counter rotation direction from 1ts U-sha ed leadin edoe in a sem1- z: o r 7 pocket formationjand has a pitclidetermined by the spacing of the radial arms of the inner a'ndouter set on the sha b.

i This device, with its air displacing and. compressing members constructed as above set forth, is veryeffective in its operation and suitable for its purpose. In its'rota tion; the" large dimension ll-shaped leading edges of the air displacing members first contact'the air, which in the continued ro tation of the device is appreciably 1 come pressed by the members as their cross sectional dimension progressively decreases in counter rotation direction. The air. thus compressed forms a substantially heavier element than mere atmospheric air against which the-pitchedfaces of the members may push in their rotation, and consequently the shape of the members permits a great trac- -t1ve:force to be'developed 111 therevolution of the device. The large area ofthe pitched faces of the air displacing and compressing members materially enhances the development of tract ve force by the device without requiring members of large radius or length,

thus making for aniore sturdy structure ofthe device as supported bythe shaft there of. i The great traction developed by this device per revolution materially lessens the speed of operation thereof required to prof duce' a given 'tractive' forceiin comparison .withithe speed required by conventional propellers,and the'device is thereforeadapted for use with relatively low speed, long lived motors at consequent greatly reduced operating costs and liferisks. I

The. weights 4 are provided as safety factor. 1 Obviousl the weighted arms of the device will have a great rotational, inertia when rotating at full" speed, and "if the motor of the plane should fail 'orstall, a

continued operation of the air displacing and compressing members I under the force of their inertia for a substantial period of time would be ofgreat advantage to a pilot in providing him with some opportunity foramaneuvermg his plane to make a landing. This would be especially helpful in low altitude flying where the range of mere glid- V reach a desirable landing place; Naturally the advantage obtained by rotationalsinertia will be small, but where the Weights are streamlined and only a low speed of operationis required the disadvantage of the added air'resistance of the weight will be overcome :by this advantage.

The invention as shown is susceptible. of Thus 7 the weights might be eliminated, the bracing of the arms might be altered or eliminated, thespecific mg might be insufficient to enable him .to

shape and number of the air displacing membersmight be changed, and many other changes could be -made without altering the basic idea of the-device, which relates to the useof pitched, tapering, semi-pocket shaped, air displacing and compressing members of large area but small radius.'. Furthermore the device is adapted for usevfor propulsion .purposes in place -of propellers of conventional construction in all devices with which the latter are used, such asspeed boats, etc.

The devioe'is also adapted for use as the operating means of a helicopter, or in an airplane topermit take off and landing with-.

of each of said air displacing membersextending from the inner end of an arm of the outer set to the outer end thereof, thence to the outer end of the parallel arm of the inner set, thence diagonally in counter rotation direction .to'the outer endiof an adjacent armof the inner set, thence to the innor end ofsaid' last named arm, and thence to the point of beginning, 7'

2. In a propulsion device, a rotatable shaftjspacedinner and outer sets'of perpendicular radial arms, and air displacing and'compressing members carried by said arms, the leading edge of-each of said members extending from the outer end ofan arm of the inner set to the outer end of. the adjacent arm of the outer set, thence in contact w1th said arm to its lnner end, and

thence to the inner end ofan adjacent arm of the inner set, said member tapermgfrom its leading edge to the outer end of said last named arm in counter rotation direction.

- 3; In a propulsion device, a rotatable shaft, a plurality of radially extendingarms carried'by said shaft, said armsbeing arranged to form inner and outer sets Jof perpendicularly disposed arms, and airldisplacingI a-nd compressing members carried by said arms, each of said members, extending 7 from a leading-edge carried by an arm of the outer set to the outer end of an adjacent arm of the inner set in a tapering semipocket form.

4. In a propulsion device, a rotatable shaft, spaced sets of radially extending arms carried by said shaft, and air displacing members carried by said arms, each of said members having a U-shaped leading edge carried by an arm of the outer set and se cured to the inner and outer endsof adjacent arms of the inner set, said members tapering from the leading edge to the outer end of the adjacent arm of the inner set in counter rotation direction.

5. In a propulsion device, a rotatable shaft, spaced sets of radially extending arms carried by said shaft, and air displacing members carried by said arms and pitched in counter rotation direction, sald members 7 having U-shaped leading edges and progressively decreasing cross section 'in counter rotation direction.

16. In a propulsion device, a rotatable shaft, spaced sets of radially extending arms carried by said shaft, and air displacing members carried by said arms in balanced relation on said shaft, each of said members tapering from a large dimension leading edge carried by an arm of the outer set to the end of an arm ofthe inner set, each member having angularly disposed sideforming portions extending from the outer to the inner arms and tapering therefrom to the end of said first named inner arm.

7, In a propulsion device, a rotatable shaft, arms carried by said shaft, air displacing and compressing members carried by said arms, weights of streamlined form carried by the outer ends of said arms, and braces carried by and extending between said weights.

8. In a propulsion device, a rotatable 'shaft, and pitched'air displacing members carried by said shaft, said members each having a U-shaped leading edge and tapering therefrom in counter rotation direction.

9. In a propulsion device, a rotatable shaft, and air displacing members carried by said shaft, said members each having a U-shaped leading edge and tapering therefrom in counter rotation direction, the trailing edge of each member being disposed in substantially the same plane as the ends of the U-shaped leading edge to form a pitched semi-pocketshaped member.

10. In a propulsion device, a rotatable vice having a rotatable shaft, of radial members carried by said shaft, and weights carried by said members and tapering toward their leading and trailing edges in streamlined form.

In testimony whereof I affix my signature.

SAM B. SMITH.

shaft, and air displacing members carried by said shaft, said air displacing members being substantially U-shaped on sections 7 transverse of the line of rotation thereof, the

transverse section of said members progres slvely decreasmg 1n counter rotatlon direction. 

